Seoul: A special-ed student attacked people with a weapon at a high school in South Korea's Cheongju on Monday, injuring seven people, including the principal and himself, officials said. 

The attack happened around 8:40 a.m. in the city, some 110 kilometres south of Seoul, when the second-grade high school student, 18, walked out of a classroom during a meeting with his counsellor and began stabbing people in the corridor.

He then walked out of the school and injured two passersby before jumping into a nearby reservoir, reports Yonhap news agency.

"I was taking my children to kindergarten and driving slowly near the school because of traffic when the student came up and knocked on the door," one of the victims, a 43-year-old surnamed Im, said.

"I opened the window, and he stabbed my face without saying anything before running away," he added.

The victims were taken to hospitals with minor to serious injuries to the chest, abdomen and other areas and are being treated there. None of them are in critical condition, officials said.

The student was rescued from the reservoir by first responders and is currently in police custody after being treated at a hospital.

Police plan to book him on suspicion of attempted murder and question him over the details of the attack.

The North Chungcheong Province Office of Education, which has jurisdiction over the school, said no students are believed to have witnessed the stabbing as it happened after classes began.

Class will run only until the seventh period on Monday and parents have been informed of the incident, the office said.

"We apologise for the unforeseen incident and will analyse the exact circumstances and cause while coming up with response measures," said Yoon Geon-young, the superintendent of education for the province. (IANS)